Add pack attribute to nb-action to customize the icon pack used in the nested nb-icons

There is no way to customize what pack is used for [nb-action](https://akveo.github.io/nebular/docs/components/actions/api#nbactionscomponent) icons as there is no [pack] input attribute like there is on [nb-icon](https://akveo.github.io/nebular/docs/components/icon/api#nbiconcomponent).

The input attribute could be added to the nb-action component and then passed to the nb-icon used within the component such as this one on line 27:
https://github.com/akveo/nebular/blob/master/src/framework/theme/components/actions/actions.component.ts#L27

### Issue type

**I'm submitting a ...** (check one with "x")

* [ ] bug report
* [x] feature request

### Issue description

**Current behavior:**

```typescript

```

### Other information:

**Angular, Nebular**
```
@angular 14.2
@nebular ~10.0.0
```